Yeah, those are good examples, along with Java or .Net or even PHP. There’s an understanding that a developer can open a file from the source code tree, look at which includes are in scope, which methods are being used, and follow the API docs on those in order to track down what’s happening. This works almost everywhere but Rails. With Rails you need to have a basic comfort with the entire ecosystem and which behaviours are globally applied, often you can’t follw the source code to know, even if you go into the Rails source, where many methods are dynamically generated.

Other responders on this thread think I’m saying Rails isn’t productive or easy to learn, I’m not. I’m saying there is a higher bar for the minimum amount of knowledge you need to comprehend the flow of control in a Rails app.

I agree those libraries are more straightforward in the sense that it's easier to track what's happening, but I feel that's only true for rather basic apps. Having done my share of Express developmnet, I know that once you need user auth, a database connection etc. you are curating your own selection of libraries, inventing your own folder structure and so on and so on.

And if you are so unlucky as to inherit such a project it is anything but straightforward. It's like trying to deschiffer the mind of some alien creature, i.e. former developer.